1. Field of the Invention
The invention relates to new compositions and a method for control of tartar and plaque formation on teeth.
2. The Related Art
Compositions with active ingredients against tartar and plaque have been disclosed in the literature. In U.S. Pat. No. 4,894,220 (Nabi et al.) is described an oral composition whose active ingredients are 2,4,4'-trichloro-2'-hydroxydiphenyl ether (hereinafter known as triclosan), alkali metal pyrophosphate and a synthetic anionic polymeric polycarboxylate (e.g. Gantrez.RTM.). Pyrophosphate and polycarboxylate provide the antitartar effect while the triclosan attacks plaque. See also U.S. Pat. No. 5,043,154 (Gaffar et al.) and U.S. Pat. No. 4,980,153 (Jackson et al.). Somewhat similar is EP 0 397 452 (Ibrahim et al.) which combines tripolyphosphate salts as the antitartar agent along with triclosan.
Although pyrophosphates are cost-effective, they have been shown to have an irritating effect on human skin and oral soft tissue. Recent reports in the dental literature suggest that pyrophosphate-containing dentifrices are harsher to oral tissues than other products. For example, B. E. Beacham et al. (Journal of the American Academy of Dermatology 22, p. 1029-1032 [1990]) found that use of pyrophosphate-containing antitartar toothpastes resulted in perioral erythema after 4 to 14 days. This condition was found to be caused by the pyrophosphate. G. Kowitz et al. (Oral Surg. Oral Med. Oral Pathol. 70, p. 529-536 [1990]) also studied the effects of medium and low doses of both flavoring agents and pyrophosphate in toothpastes, and found that higher rates of mucosal reactions such as ulceration, sloughing, and erythema were caused predominantly by the pyrophosphate Other common ingredients such as detergents (sodium lauryl sulfate) and flavoring agents are known in the art to cause irritation to skin and oral tissue. The result of such irritation is health risks upon long-term exposure or, at minimum, poor consumer perception due to burning sensation, irritation and flaking/dryness associated with use of such products.
In addition, products having combinations of pyrophosphate and triclosan, though desirable for their oral benefit, are also irritating to skin tissue. Zinc/triclosan combinations give similar gum health benefit but zinc levels must be held below about 2% because of its undesirable metallic taste and astringency. Clearly, combinations of agents potentially give desirable benefits but are limited by safety concerns and aesthetic effects of common commercial agents.
Accordingly, it is an object of the present invention to provide compositions for use in the oral cavity having both improved antitartar and antiplaque effectiveness.
A further object of the present invention is to provide compositions for use in the oral cavity that control tartar and plaque formation but are also nonirritating on the mucosal areas of the mouth.
A still further object of the present invention is to provide a method for controlling tartar and plaque formation that results in a less irritating application than heretofore achievable.
These and other objects of the present invention will become more apparent by consideration of the following summary, detailed description and Examples.